Method for radiation conversion with bismuth borate crystals

Abstract

Bismuth borates in crystalline form with non-linearly optical properties. Bismuth borate crystals are used for radiation conversion. The crystal is created with non-linearly optical properties which has non-linearly optical coefficients which exceed those of crystals used hitherto in the application and which is easy, inexpensive to produce and of high optical quality.

What is claimed is:  
     
       1. A crystal with non-linear optical properties of the chemical composition Bi 1-x M x B 3 O 6 , wherein M is selected from the group consisting of Ga, In, Sc and the rare earth elements and x is of a value greater than 0 and less than or equal to 0.5. 
     
     
       2. A crystal according to claim  1  characterised in that the crystal is a single crystal. 
     
     
       3. A method for converting the frequency of coherent radiation, the method comprising passing the coherent radiation through a crystal having the composition Bi 1-x M x B 3 O 6 , wherein M is selected from the group consisting of Ba, In, Sc, and the rare earth elements, x being greater than or equal to 0 and less than or equal to 0.5. 
     
     
       4. A method according to claim  3  wherein the crystal is a single crystal. 
     
     
       5. A method according to claim  4  wherein the crystal is a polycrystal having at least one single crystal layer. 
     
     
       6. A method according to claim  3  wherein a laser resonator is employed, the crystal being provided within the laser resonator for doubling the frequency of the coherent radiation. 
     
     
       7. A method according to claim  3  wherein a laser resonator is employed, the crystal being provided outside the laser resonator for doubling the frequency of the coherent radiation. 
     
     
       8. A method according to claim  6  wherein the source of the coherent radiation is a Nd solid state laser. 
     
     
       9. A method according to claim  7  wherein the source of the coherent radiation is a Nd solid state laser. 
     
     
       10. A method according to claim  6  wherein the source of the coherent radiation is a laser diode. 
     
     
       11. A method according to claim  7  wherein the source of the coherent radiation is a laser diode. 
     
     
       12. A method according to claim  3  wherein the coherent radiation comprises coherent radiation from a first source having a first frequency, and coherent radiation from a second source having a second frequency, the frequency of the coherent radiation being converted by mixing the radiation from the first source with the radiation from the second source. 
     
     
       13. A method according to claim  12  wherein a laser resonator is employed, the mixing occurring within a laser resonator. 
     
     
       14. A method according to claim  12  wherein a laser resonator is employed, the mixing occurring outside a laser resonator. 
     
     
       15. A method according to claim  12  wherein the first source provides a fundamental wave of coherent radiation having a frequency ω, the crystal being the second source and providing a first harmonic wave of coherent radiation having a frequency  2 ω, the fundamental wave and the first harmonic wave being mixed to provide a second harmonic wave having a frequency  3 ω. 
     
     
       16. A method according to claim  3  wherein the coherent radiation comprises coherent radiation from a first source having a first frequency, and coherent radiation from a second source having a second frequency, the frequency of the coherent radiation being converted to provide the difference in frequency between the radiation from the first source with the radiation from the second source. 
     
     
       17. A method according to claim  16  wherein a laser resonator is employed, the crystal being provided within the laser resonator. 
     
     
       18. A method according to claim  16  wherein a laser resonator is employed, the crystal being provided outside the laser resonator. 
     
     
       19. A method according to claim  3  wherein the coherent radiation comprises a pump wave of frequency ω 82 , the crystal being provided within a parametric optical oscillator. 
     
     
       20. A method according to claim  3  wherein the coherent radiation comprises a pump wave of frequency ω 82  , the crystal being provided within a parametric optical amplifier. 
     
     
       21. A parametric optical oscillator comprising a crystal having the composition Bi 1-x M x B 3 O 6 , wherein M is selected from the group consisting of Ba, In, Sc, and the rare earth elements, x being greater than or equal to 0 and less than or equal to 0.5. 
     
     
       22. A parametric optical amplifier comprising a crystal having the composition Bi 1-x M x B 3 O 6 , wherein M is selected from the group consisting of Ba, In, Sc, and the rare earth elements, x being greater than or equal to 0 and less than or equal to 0.5. 
     
     
       23. A tunable laser system comprising a crystal having the composition Bi 1-x M x B 3 O 6 , wherein M is selected from the group consisting of Ba, In, Sc, and the rare earth elements, x being greater than or equal to 0 and less than or equal to 0.5. 
     
     
       24. An optical projection system comprising a crystal having the composition Bi 1-x M x B 3 O 6 , wherein M is selected from the group consisting of Ba, In, Sc, and the rare earth elements, x being greater than or equal to 0 and less than or equal to 0.5.